1. Field of the Invention
The present invention relates to a stack-type piezoelectric device used as a drive source for small displacement, such as control of a valve of a micropump.
2. Related Background Art
An example of the conventional stack-type piezoelectric devices is the one described in Japanese Patent Application Laid-Open No. 2002-254634. This stack-type piezoelectric device consists of an alternate stack of piezoelectric layers in each of which a number of individual electrodes are formed in a pattern, and piezoelectric layers in each of which a common electrode is formed in a pattern, and the individual electrodes aligned in the thickness direction of the stack-type piezoelectric device are connected by electroconductive members through through holes formed in the piezoelectric layers. In this stack-type piezoelectric device, when a voltage is applied between predetermined individual electrodes and common electrodes, active parts (portions to be distorted by piezoelectric effect) corresponding to the predetermined individual electrodes in the piezoelectric layers are selectively displaced.